It'll probably be in there. It's in pretty much every new source game released by Valve, including TF2 and HL2.

Unfortunately not at the moment, but I bet it is coming or there's probably a work around.

Quote from FAQ:

"
Key Information

* Alien Swarm is being released for free by Valve.
* Is a tactical, 4 player co-op action game with a top-down perspective.
* Complete game code and mod tools available to the community.
* The SDK is separate from that of other Source games.
* Features 4 unique classes.
* Over 40 weapons and equipment with many configurations.
* 8 unique characters.
* Has Easy, Normal, Hard, and Insane difficulties.
* Features only Campaign Mode and Offline Practice Mode.
* Uses L4D2 style add-on system for custom campaigns.
* Much less randomization than L4D so players can observe, learn, and overcome challenges.
* Uses a modified Source engine between the L4D2 and Portal 2 iterations.
* Supports dedicated and listen servers.
* Contains Valve game easter eggs.
* 64 achievements
* Does not currently support Mac or controllers.
"

Have a feeling controller support will be relatively easy especially if you use a 360 controller since windows will recognize them. PS3 controllers will probably be alot harder to recognize.

Unfortunately not at the moment, but I bet it is coming or there's probably a work around.

Quote from FAQ:

"
Key Information

* Alien Swarm is being released for free by Valve.
* Is a tactical, 4 player co-op action game with a top-down perspective.
* Complete game code and mod tools available to the community.
* The SDK is separate from that of other Source games.
* Features 4 unique classes.
* Over 40 weapons and equipment with many configurations.
* 8 unique characters.
* Has Easy, Normal, Hard, and Insane difficulties.
* Features only Campaign Mode and Offline Practice Mode.
* Uses L4D2 style add-on system for custom campaigns.
* Much less randomization than L4D so players can observe, learn, and overcome challenges.
* Uses a modified Source engine between the L4D2 and Portal 2 iterations.
* Supports dedicated and listen servers.
* Contains Valve game easter eggs.
* 64 achievements
* Does not currently support Mac or controllers.
"

Have a feeling controller support will be relatively easy especially if you use a 360 controller since windows will recognize them. PS3 controllers will probably be alot harder to recognize.

quite handily i would imagine, versus like a FPS which quite frankly is subpar with a controller.

You would still need to target precisely with one of the sticks. Just picking a direction to spray in, a la Robotron 2084 / Smash TV, won't work here. Sounds pretty awkward to me.

With a mouse there's a consistent connection between your hand and the target; keep your hand still and the cursor stays in place. With a stick you'd need the sensitivity up very high in order to snap around and fire behind you. Keeping precise aim vs moving targets with that sort of sensitivity is going to be pretty nasty. I can't think of a single game where this is at all pleasant.

Do you propose just doing away with the reticle? How will you heal teammates who are lined up behind one another?